A clinical study on mix-and-match COVID-19 vaccines has found that booster shots with the Moderna vaccine are the most effective, the study’s lead researcher said yesterday. The study, which began in December last year at Chang Gung Memorial Hospital and whose results were published yesterday, involved 340 participants with an average age of 35 who had received two doses of the AstraZeneca COVID-19 vaccine, lead researcher Chiu Cheng-hsun (邱政洵), who is the vice superintendent of the hospital’s branch in New Taipei City’s Linkou District (林口), told a news conference. The partici...